// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

#pragma once

#include <stddef.h>

#include <stdint.h>

#include "common/compiler_util.h" // IWYU pragma: keep

#include "common/status.h"

#include "core/data_type/data_type.h"

#include "format/parquet/decoder.h"

#include "util/bit_stream_utils.h"

#include "util/bit_stream_utils.inline.h"

#include "util/slice.h"

namespace doris {

class ColumnSelectVector;

} // namespace doris

namespace doris {

/// Decoder bit-packed boolean-encoded values.

/// Implementation from https://github.com/apache/impala/blob/master/be/src/exec/parquet/parquet-bool-decoder.h

//bit-packed-run-len and rle-run-len must be in the range [1, 2^31 - 1].

// This means that a Parquet implementation can always store the run length in a signed 32-bit integer

class BoolPlainDecoder final : public Decoder {

public:

    BoolPlainDecoder() = default;

    ~BoolPlainDecoder() override = default;

    // Set the data to be decoded

    Status set_data(Slice* data) override {

        bool_values_.Reset((const uint8_t*)data->data, data->size);

        num_unpacked_values_ = 0;

        unpacked_value_idx_ = 0;

        _offset = 0;

        return Status::OK();

    }

    Status decode_values(MutableColumnPtr& doris_column, DataTypePtr& data_type,

                         ColumnSelectVector& select_vector, bool is_dict_filter) override;

    template <bool has_filter>

    Status _decode_values(MutableColumnPtr& doris_column, DataTypePtr& data_type,

                          ColumnSelectVector& select_vector, bool is_dict_filter);

    Status skip_values(size_t num_values) override;

protected:

    inline bool _decode_value(bool* value) {

        if (LIKELY(unpacked_value_idx_ < num_unpacked_values_)) {

            *value = unpacked_values_[unpacked_value_idx_++];

        } else {

            num_unpacked_values_ =

                    bool_values_.UnpackBatch(1, UNPACKED_BUFFER_LEN, &unpacked_values_[0]);

            if (UNLIKELY(num_unpacked_values_ == 0)) {

                return false;

            }

            *value = unpacked_values_[0];

            unpacked_value_idx_ = 1;

        }

        return true;

    }

    /// A buffer to store unpacked values. Must be a multiple of 32 size to use the

    /// batch-oriented interface of BatchedBitReader. We use uint8_t instead of bool because

    /// bit unpacking is only supported for unsigned integers. The values are converted to

    /// bool when returned to the user.

    static const int UNPACKED_BUFFER_LEN = 128;

    uint8_t unpacked_values_[UNPACKED_BUFFER_LEN];

    /// The number of valid values in 'unpacked_values_'.

    int num_unpacked_values_ = 0;

    /// The next value to return from 'unpacked_values_'.

    int unpacked_value_idx_ = 0;

    /// Bit packed decoder, used if 'encoding_' is PLAIN.

    BatchedBitReader bool_values_;

};

} // namespace doris